The negative was a 4x5. I cut that from a 14x17 sheet. There are several sizes available and suppliers seem to be easy to find - here is one page-http://www.med1online.com/c-289-pb7.aspx
We pay about $100 for 100 sheets of 14x17. The only thing I'm still worried about is development. Like I said in my first post, I used the company's processor for these first negatives and I think there will be a bit of experimentation to find a good home set of times and chemicals.

As I said, i wouldn't worry about home processing. Most X-Ray developers are simply hydroquinone and an alkali in solution; very simple. They're also VERY cheap, so you could buy them from a supplier. I'd start with a hydroquinone or hydroquinone - metol developer (Dektol or D-76 or the like). Fixing and stopping would obviously be standard.

Damn, $36 for 100 sheets of 8x10 -- that's cheaper than lith film, competitive with *paper*! And would I be correct in thinking the designation "half speed" suggests there's a faster version also, possibly equivalent to something like ISO 50? Ah, yes, I see it now, "full speed" blue sensitive. Any idea what the speed is on the orthochromatic version? And any suggestions why the 14x17 is so much more than the 30x35?

It doesn't suprise me to see good tonality in the original radiologic process -- I've seen medical X-ray film with very nice, subtle gray shading; we just don't think of it as pictorial because we usually see it as a negative shadowgram with relatively unfamiliar subject matter.

From what I've seen, X-ray film is processed at a higher temperature than regular film. The one MSDS that I saw for the developer seems to indicate that they're mainly hydroquinone developers.

X-ray films come in multiple types. Ones that are used for non-screen x-ray imaging are minimally hardened and they are not very good at higher temperature, unless the developer contains a hardener. Screen-exposure type is probably made ok with higher temp.

X-ray developers are usually MQ or PQ developer like D-19. Dektol 1+1 or 1+2 would be close enough.

For over twenty years I used Kodak X-Ray film on everything from single phase machines to Linear Accelerators in cassettes with lead called beam films used in Radiation Therapy. X-Ray films have a double emulsion and are used in cassettes with two rare earth screens to cut down on the amount of radiation needed to make an X-Ray image. The film doesn't even make a good pinhole image. Common sizes are 8x10, 10x12, 11x14, 7x17, and 14x17. I used so much of all of these sizes that 4x5 seems like micro size. 90 seconds through a Kodak X-Omat processor and you have a dry X-Ray ready for the Doctor. The new filmless generation is an X-Ray, because it can go through the body, and Ionized plates which replaces the film, good bye film and dirty chemicals.

General Photographic film is for US, that's you and me, and is the film of choice not X-Ray film, unless you get a license and buy an X-Ray machine and want to see inside of things. I have X-Rayed a lot of things, bodies not included, like my watch for example, all in the name of science and knowledge of course.

Well, I'm getting some sample film by hte end of hte week, so I'll play around with it and see. I'm also trying to get my hands on some IR laser film, which is designed for printing in IR laser printers.

It's an orthochromatic film with deep red and IR sensitivity (the curves I've seen extend out to about 850 - 900nm), though its contrast is REALLY HIGH; some of the curves for contrast are pretty darned close to vertical - but maybe this can be tamed? The prices are a bit more than X-Ray film, but it's still not bad ...

Has anyone here used a zone plate or pinhole to focus ambient x-ray radiation and produce an image without using a device to emit x-rays? I know that a chest x-ray is the equivalent of several days of background, so I would expect the exposure time needed to be very lengthy.

X-Ray films have a double emulsion and are used in cassettes with two rare earth screens to cut down on the amount of radiation needed to make an X-Ray image.

That's called screen exposure x-ray film. As you said, it requires smaller dose of x-ray than direct exposure (non-screen type) but the resolution is much poorer than direct exposure films.

Screen type films are at least optimized for green light exposure lasting for a few seconds.

One thing with direct exposure films is that, they are usually large grain bromide emulsions to increase x-ray sensitivity, and they are also doped with agents to enhance x-ray sensitivity. Many of these parameters are optimized for x-ray and of course not visual light, so light sensitivity may be quite disappointing for the grain size. And it's only blue sensitive.